Flaps are hinged surfaces on the trailing or leading edges of the wings of a fixed wing aircraft which when activated change the coefficient of lift and drag of the wing. There are many and various kinds of flaps, all of which are hinged to the airfoil section of the wing at either the trailing or leading edge thereof or indeed at both. However, they all require actuation to bring them into an operational or parked position in relation to the airfoil section. Conventionally hydraulic or electro-hydraulic systems have been used for this purpose, thus adding to the complexity and the expense of the aircraft and to its operating costs in terms of repair and maintenance. Apart from the actuation of the flaps, the design of the linkages employed to effect the desired movement is often itself complicated. For example, pivoted parallelogram frames are used and clearly the more complex the linkage design the greater is the potential for failure. Accordingly, a safety issue also arises. Accordingly, there is a need for an improved flap device obviating the disadvantages of conventional flap systems whilst providing a simpler and more effective mechanism for performing the same function.